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Title: Ultrafast carriers dynamics in filled-skutterudites

Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4–0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.
Authors:
;  [1] ;  [2]
  1. School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)
  2. Chemical and Materials Systems Laboratory, GM Global R and D, Warren, Michigan 48090 (United States)
Publication Date:
OSTI Identifier:
22412551
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 23; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CHARGE CARRIERS; ENERGY LEVELS; KRAMERS-KRONIG CORRELATION; LASERS; PHONONS; RELAXATION TIME; SPECTROSCOPY; THERMOELECTRIC MATERIALS